It is common that what once seemed to be impossible in the past is now commonplace. In other words, there is always a shift between un-commonsense (hi-joshiki) and commonsense (joshiki). Thus, it is necessary to reconsider these issues, such as what quality can be described as commonsense and what is the basis of commonsense. However, it is not easy to conceive of the basis of commonsense because it seems to be not only self-evident, but also vague. To avoid such an esoteric point, a Japanese philosopher, Yujiro Nakamura, considered “sensus communis” (kyotsu kannkaku) as the basis of commonsense and he focused on this concept. The English word “commonsense” is always translated to the Japanese word “joshiki” and commonsense originates from the Latin word “senses communis.” Thus, Nakamura translated the Latin expression as “kyotsu kankaku.” Therefore, commonsense can be also translated to “kyotsu kankaku.” Is there any more intrinsic relationship between “joshiki” and “kyotsu kankaku,” except that they are both the Japanese translations of “commonsense”? In Nakamura’s opinion, “joshiki” and “kyotsu kankaku” are the external and internal aspects of commonsense, respectively, i.e., they are two sides of the same coin. In this paper, based on Nakamura’s book Kyotsu Kankaku Ron, I will try to explore the connotation of “kyotsu kankaku” to seek the basis of “joshiki” and clarify what it means to people in the society.